Mixtures of two host materials and organic electroluminescent devices comprising said mixtures

Abstract

The present invention relates to an organic electroluminescent device containing a mixture comprising an electron transport host material and a hole transport host material, a formulation containing the mixture of host materials and a mixture containing the host materials. The electron transport host material corresponds to a compound of formula (1) of the class of compounds containing two triazine units. The hole transport host material corresponds to a compound of formula (2) of the class of bis-carbazoles or derivatives thereof.

Description

[0001] This invention relates to organic electroluminescent devices comprising a mixture of an electron transport host material and a hole transport host material, and to formulations comprising the mixture of said host materials and mixtures comprising said host materials. The electron transport host material corresponds to compounds of formula (1) below, belonging to the category of compounds containing two triazine units. The hole transport host material corresponds to compounds of formula (2) below, belonging to the category of bicarbazoles or their derivatives.

[0002] The structures of organic electroluminescent devices (such as OLEDs—organic light-emitting diodes, or OLECs—organic light-emitting electrochemical cells) that use organic semiconductors as functional materials are already well-known. In addition to fluorescent emitters, the luminescent materials used here are increasingly organometallic complexes that exhibit phosphorescence rather than fluorescence. For quantum mechanical reasons, using organometallic compounds as phosphorescent emitters can improve energy and power efficiency by up to four times. However, generally speaking, in the case of OLEDs, especially in the case of OLEDs displaying triplet emission (phosphorescence), improvements are still needed, particularly in terms of efficiency, operating voltage, and lifetime.

[0003] The performance of organic electroluminescent devices depends not only on the light emitter used. In particular, other materials used, such as host and matrix materials, hole-blocking materials, electron transport materials, and electron or exciton-blocking materials, especially the host or matrix materials, are also crucial. Improvements in these materials can lead to significant improvements in electroluminescent devices.

[0004] The host materials used in organic electronic devices are well known to those skilled in the art. In the prior art, the term "matrix material" is often used when referring to the host material of phosphorescent emitters. This use of the term also applies to the present invention. Furthermore, various host materials have been developed for fluorescent and phosphorescent electronic devices.

[0005] Another way to improve the performance data of electronic devices, especially organic electroluminescent devices, is to use two or more materials, particularly a combination of host or matrix materials.

[0006] US 6,392,250 B1 discloses the use of a mixture of electron transport materials, hole transport materials, and phosphors in the light-emitting layer of an OLED. This mixture could potentially improve the lifespan of OLEDs compared to existing technologies.

[0007] US 6,803,720 B1 discloses the use of a mixture comprising a phosphorescent emitter, a hole transport material, and an electron transport material in the light-emitting layer of an OLED. Here, both the hole transport material and the electron transport material are small organic molecules.

[0008] KR20100131745 describes specific linked bistriazine compounds and their use as host materials in organic electroluminescent devices. Devices containing these bistriazine compounds and indole-carbazole compounds as additional host materials in the light-emitting layer are also described.

[0009] WO2012048779 discloses an ink for organic electroluminescent devices comprising a carbazole compound, an electron transport compound, a triplet emitting compound, and at least one solvent, wherein the electron transport compound comprises a ketone compound or a triazine compound, which may also be a specifically linked triazine compound, and wherein the carbazole compound contains at least two carbazole groups that are linked to each other via their N atoms.

[0010] US20140299192 discloses a specific linked bistriazine compound and its use in organic electroluminescent devices, particularly as an electron transport material.

[0011] JP2015106658 also specifically describes dibenzofuran compounds substituted at the 2 and 8 positions with 4,6-diphenyl-1,3,5-triazine-2-ylphenyl, and their use together with other host materials as host materials in organic electroluminescent devices.

[0012] WO2015169412 describes a compound containing two triazine units that can be used together with other host materials as a host material in organic electroluminescent devices.

[0013] US2016329502 discloses an organic electroluminescent device containing a light-emitting layer, the light-emitting layer comprising three components: a first host material, a compound according to the invention serving as a second host material, and a light emitter, wherein the compound according to the invention may contain two triazine units.

[0014] US20170054087 describes specific triazine derivatives and their use as host materials in light-emitting electronic devices together with other host materials.

[0015] WO2017178311 describes specific dibenzofuran or dibenzothiophene compounds that may have two triazine substituents, and their use in organic electroluminescent devices, wherein these compounds may also be used as host materials. Furthermore, it describes how this type of compound can be combined with other host materials. Table 1 describes, for example, the structure of an organic light-emitting diode (E11) containing two host materials in its light-emitting layer, wherein 7,7-dimethyl-5-phenyl-2-(9-phenylcarbazole-3-yl)indeno[2,1-b]carbazole is used as the second host material.

[0016] CN108250189 describes specific dibenzofuran or dibenzothiophene compounds that may have two triazine substituents, and their use as host materials in organic electroluminescent devices.

[0017] US2019013490 describes the use of specific dibenzofuran compounds or dibenzothiophene compounds, and their combination with other host materials as host materials.

[0018] WO19017730 describes specific dibenzofuran or dibenzothiophene compounds and their use as host materials.

[0019] WO19122899 describes specific bistriazine compounds and their use together with luminescent materials as host materials in luminescent layers.

[0020] However, improvements are still needed in the use of these materials or mixtures thereof, particularly in terms of the efficiency, operating voltage, and / or lifetime of organic electroluminescent devices.

[0021] Therefore, the object of the present invention is to provide a combination of body materials suitable for organic electroluminescent devices, particularly for fluorescent or phosphorescent OLEDs, and especially for resulting in good device performance in terms of improved lifetime, and to provide corresponding electroluminescent devices.

[0022] It has been found that the combination of at least one compound of formula (1) as a first host material and at least one hole transport compound of formula (2) as a second host material in the emitting layer of an organic electroluminescent device achieves this objective and overcomes the shortcomings of the prior art. Using this type of material combination to produce the emitting layer in organic electroluminescent devices results in these devices exhibiting very good performance, particularly in terms of lifetime, and especially at the same or improved efficiency and / or operating voltage. The advantages are also evident, particularly in the presence of the emitting component in the emitting layer, especially when combined with the emitting element of formula (3) at a concentration between 2% and 15% by weight.

[0023] Therefore, the present invention first relates to an organic electroluminescent device, comprising an anode, a cathode, and at least one organic layer, said at least one organic layer comprising at least one light-emitting layer, wherein said at least one light-emitting layer comprises at least one compound of formula (1) as host material 1 and at least one compound of formula (2) as host material 2.

[0024]

[0025]

[0026] The following applies to the symbols and markings used:

[0027] Y is selected from O, S, C(CH3)2, C(phenyl)2 or The * symbol marks the C atom that is bonded to the rest of the formula (1);

[0028] L is selected from one of the divalent linker groups L-1 to L-26.

[0029]

[0030] The linking groups L-1 to L-26 may also be replaced by one or more substituents R;

[0031] W is O, S, or C(CH3)2; preferably O or S;

[0032] a is 0 or 1;

[0033] b is 0 or 1;

[0034] R is selected from CN each time it appears, either identically or differently, of a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 20 C atoms, of an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, of an aryloxy or heteroaromatic group having 5 to 40 aromatic ring atoms, or of an aralkyl or heteroaromatic group having 5 to 40 aromatic ring atoms;

[0035] Ar1, each time it appears, is independently of each other an aryl or heteroaryl group having 5 to 40 aromatic ring atoms, which can be substituted by one or more groups R;

[0036] K and M are, in each case, independent of each other, aromatic ring systems having 6 to 40 aromatic ring atoms, which are unsubstituted, partially or completely deuterated, or monosubstituted by R*, provided that x and y represent 0 and x1 and y1 represent 0, or

[0037] K and M are independent of each other with X or X in each case. 1 Together they form a heteroaromatic ring system with 14 to 40 ring atoms, provided that the values ​​of x, x1, y and / or y1 represent 1;

[0038] x and x1 are 0 or 1 independently of each other in each case;

[0039] y and y1 are 0 or 1 independently of each other in each case;

[0040] X and X 1 In each case, it is a key or C(R#)2 that occurs independently of each other each time;

[0041] R 0 Each time they appear, they are independent of each other as aromatic ring systems with 6 to 18 C atoms that are either unsubstituted or partially or completely deuterated;

[0042] R* is dibenzofuranyl or dibenzothiophenylyl;

[0043] R# is an alkyl group, either straight-chain or branched, having 1 to 4 carbon atoms, which appears independently of each other.

[0044] c, d, e, and f are each 0 or 1 independently.

[0045] The present invention also covers methods for producing organic electroluminescent devices and mixtures comprising at least one compound of formula (1) and at least one compound of formula (2), specific combinations of materials, and formulations comprising such mixtures or combinations of materials. The present invention also relates to the corresponding preferred embodiments described below. Surprising and advantageous effects are achieved through specific selection of compounds of formula (1) and compounds of formula (2).

[0046] Organic electroluminescent devices according to the present invention include, for example, organic light-emitting transistors (OLETs), organic field quenching devices (OFQDs), organic light-emitting electrochemical cells (OLECs, LECs, LEECs), organic laser diodes (O-lasers), or organic light-emitting diodes (OLEDs). The organic electroluminescent devices according to the present invention are particularly organic light-emitting diodes or organic light-emitting electrochemical cells. OLEDs are especially preferred among the devices according to the present invention.

[0047] The organic layer of the device according to the invention comprises a material combination containing at least one compound of formula (1) and at least one compound of formula (2) as described above or below, preferably including, in addition to the light-emitting layer (EML), a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), an electron injection layer (EIL), and / or a hole blocking layer (HBL). The device according to the invention may also include multiple layers selected from EML, HIL, HTL, ETL, EIL, and HBL.

[0048] However, the device may also contain inorganic materials or may include a layer composed entirely of inorganic materials.

[0049] The preferred light-emitting layer comprising at least one compound of formula (1) and at least one compound of formula (2) is a phosphorescent layer, characterized in that, in addition to the host-material combination of the compounds of formula (1) and (2) as described above, it also comprises at least one phosphorescent emitter. The suitable selection of the emitter and preferred emitter is described below.

[0050] The aryl group in the sense of this invention contains 6 to 40 aromatic ring atoms, preferably carbon atoms. The heteroaryl group in the sense of this invention contains 5 to 40 aromatic ring atoms, wherein the ring atoms include carbon atoms and at least one heteroatom, provided that the total number of carbon atoms and heteroatoms is at least 5. The heteroatom is preferably selected from N, O, and / or S. Here, aryl group or heteroaryl group is considered to refer to a simple aromatic ring derived from benzene, i.e., phenyl, or, for example, a simple heteroaryl ring derived from pyridine, pyrimidine, or thiophene, or, for example, a fused aryl or heteroaryl group derived from naphthalene, anthracene, phenanthrene, quinoline, or isoquinoline. Therefore, an aryl group having 6 to 18 carbon atoms is preferably phenyl, naphthyl, phenanthrene, or biphenylidene, wherein the bonding of the aryl group as a substituent is not limited. The aryl or heteroaryl group in the sense of this invention may contain one or more substituents R, wherein the substituents R are as described below.

[0051] The aromatic ring system in this invention contains 6 to 40 carbon atoms. The aromatic ring system also includes aryl groups as described above.

[0052] The aromatic ring system having 6 to 18 carbon atoms is preferably selected from phenyl, biphenyl, naphthyl, phenanthryl and triphenylide.

[0053] The heteroaromatic ring system in this invention contains 5 to 40 ring atoms and at least one heteroatom. A preferred heteroaromatic ring system has 10 to 40 ring atoms and at least one heteroatom. The heteroaromatic ring system further includes heteroaryl groups as described above. The heteroatom in the heteroaromatic ring system is preferably selected from N, O, and / or S.

[0054] For the purposes of this invention, aromatic or heteroaromatic ring systems are considered to refer to systems that do not necessarily contain only aryl or heteroaromatic groups, but in which some aryl or heteroaromatic groups may be interrupted by non-aromatic units (preferably less than 10% of non-H atoms), such as C, N, or O atoms or carbonyl groups. Thus, systems such as 9,9'-spirodifluorene, 9,9-diarylfluorene, triarylamines, diaryl ethers, piracene, etc., are intended to be considered aromatic or heteroaromatic ring systems in the sense of this invention, as are systems in which two or more aryl groups are interrupted, for example, by straight-chain or cyclic alkyl groups or by silyl groups. The definition of aromatic or heteroaromatic ring systems also covers systems in which two or more aryl or heteroaromatic groups are directly bonded to each other, such as biphenyl, terphenyl, tetraphenyl, or bipyridine.

[0055] Aromatic or heteroaromatic ring systems having 5 to 40 ring atoms that can be linked at any desired position on an aromatic or heteroaromatic ring are considered to refer to groups derived, for example, from the following substances: benzene, naphthalene, anthracene, benzo[a]anthracene, phenanthrene, benzo[a]phenanthrene, pyrene, leucine, perylene, fluoranthene, benzo[a]fluoranthene, tetraphenyl, pentaphenyl, benzo[a]pyrene, biphenyl, diphenylidene, terphenyl, terphenylidene, fluorene, spirofluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis or trans indo[a]fluorene, cis or trans monobenzyl. ⇌ indoxoruben, cis or trans dibenzo-indoxoruben, trimer indene, isotrimer indene, spirotrimer indene, spiroisotrimer indene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, indole-carbazole, indoxorubenazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenanthridine Azides, pyrazoles, indazoles, imidazoles, benzimidazoles, naphthiazoles, phenanthreneimidazoles, pyridinium imidazoles, pyrazinium imidazoles, quinoxaline imidazoles azole, benzo[ azole, naphtho azole, anthraquinone azole, phenanthrene azole, isotonic Azole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, 1,5-diazathane, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazaperylene, pyrazine, phenazine, phenazine Azides, phenothiazines, fluorescent rings, naphthidine, azacarbazole, benzo[a]carbline, phenanthroline, 1,2,3-triazoles, 1,2,4-triazoles, benzo[a]triazoles, 1,2,3- diazole, 1,2,4- diazole, 1,2,5- diazole, 1,3,4- Diazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazolium, 1,2,4,5-tetraazine, 1,2,3,4-tetraazine, 1,2,3,5-tetraazine, purine, pteridine, indoleazine, and benzothiadiazole.

[0056] The abbreviation Ar1, each time it appears, independently refers to an aryl or heteroaryl group having 5 to 40 aromatic ring atoms, which may be substituted by one or more groups R, wherein the groups R have the meaning as described above or below.

[0057] In the context of this invention, cyclic alkyl, alkoxy, or thioalkyl groups are considered to refer to monocyclic, bicyclic, or polycyclic groups.

[0058] For the purposes of this invention, straight-chain, branched, or cyclic C1 to C 20 Alkyl groups are considered to refer to groups such as: methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, 2-methylbutyl, n-pentyl, sec-pentyl, tert-pentyl, 2-pentyl, neopentyl, cyclopentyl, n-hexyl, sec-hexyl, tert-hexyl, 2-hexyl, 3-hexyl, neohexyl, cyclohexyl, 1-methylcyclopentyl, 2-methylpentyl, n-heptyl, 2-heptyl, 3-heptyl, 4 ... 2-heptyl, 3-heptyl, 4-methylcyclopentyl, 2-methylcyclopentyl, 2-heptyl, 3-heptyl, 4-methylcyclopentyl, 2-methylcyclopentyl, 2-heptyl, 2-heptyl, 3-heptyl, 4-methylcyclopentyl, 2-methylcyclopentyl, 2-heptyl, 2-heptyl, 3-heptyl, 4-methylcyclopentyl, 2-methylcyclopentyl, 2-heptyl, 2-heptyl, 4-methylcyclopentyl, 2-methylcyclopentyl, 2-heptyl, 2-heptyl, 4-methylcyclopentyl, 2-methylcyclopentyl, 2-heptyl, 2-heptyl, 2-heptyl, 4 -Heptyl, cycloheptyl, 1-methylcyclohexyl, n-octyl, 2-ethylhexyl, cyclooctyl, 1-bicyclo[2,2,2]octyl, 2-bicyclo[2,2,2]octyl, 2-(2,6-dimethyl)octyl, 3-(3,7-dimethyl)octyl, adamantyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, 1,1-dimethyl-n-hex-1-yl, 1,1-dimethyl-n-hept-1-yl, 1,1 -Dimethyl-n-octyl-1-yl, 1,1-dimethyl-n-decyl-1-yl, 1,1-dimethyl-n-dodecyl-1-yl, 1,1-dimethyl-n-tetradecyl-1-yl, 1,1-dimethyl-n-hexadecyl-1-yl, 1,1-dimethyl-n-octadecyl-1-yl, 1,1-diethyl-n-hexyl-1-yl, 1,1-diethyl-n-heptyl-1-yl, 1,1-diethyl-n-octyl-1-yl, 1,1-diethyl-n-octyl-1-yl 1,1-diethyl-n-decane-1-yl, 1,1-diethyl-n-tetradecane-1-yl, 1,1-diethyl-n-hexadecane-1-yl, 1,1-diethyl-n-octadecane-1-yl, 1-(n-propyl)cyclohexyl-1-yl, 1-(n-butyl)cyclohexyl-1-yl, 1-(n-hexyl)cyclohexyl-1-yl, 1-(n-octyl)cyclohexyl-1-yl and 1-(n-decane)cyclohexyl-1-yl.

[0059] C1 to C1 of straight or branched chains 20The alkoxy group is considered to refer to, for example, methoxy, trifluoromethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, or 2-methylbutoxy.

[0060] Straight chain C1 to C 20 Thioalkyl groups are considered to refer to, for example, S-alkyl groups, such as thiomethyl, 1-thioethyl, 1-thio-isopropyl, 1-thio-n-propyl, 1-thioisobutyl, 1-thio-n-butyl, or 1-thio-tert-butyl.

[0061] An aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms represents an O-aryl or O-heteroaryl group and refers to an aryl or heteroaryl group bonded via an oxygen atom, wherein the aryl or heteroaryl group has the meaning as described above.

[0062] An aryl or heteroaryl group having 5 to 40 aromatic ring atoms refers to an alkyl group as described above that has been replaced by an aryl or heteroaryl group, wherein the aryl or heteroaryl group has the meaning described above.

[0063] In this invention, a phosphorescent emitter is a compound that exhibits luminescence from an excited state with high spin multiplicity, i.e., spin > 1, particularly from an excited triplet state. For the purposes of this application, all luminescent complexes containing transition metals or lanthanides are intended to be considered phosphorescent emitters. A more precise definition is given below.

[0064] If the host material of the luminescent layer comprising at least one compound of formula (1) as described above or preferably as described below and at least one compound of formula (2) as described above or as described below is used in a phosphorescent emitter, it is preferred that its triplet energy is not significantly less than the triplet energy of the phosphorescent emitter. The following preferably applies to the triplet energy levels: T1(emissor) – T1(matrix) ≤ 0.2 eV, particularly preferably ≤ 0.15 eV, very particularly preferably ≤ 0.1 eV, where T1(matrix) is the triplet energy level of the matrix material in the luminescent layer, wherein this condition applies to each of the two matrix materials, and T1(emissor) is the triplet energy level of the phosphorescent emitter. If the luminescent layer contains more than two matrix materials, the above relationship preferably also applies to each additional matrix material.

[0065] The following describes the main material 1 present in the device according to the invention and its preferred embodiments. The preferred embodiments of the main material 1 of formula (1) are also applicable to mixtures and / or formulations according to the invention.

[0066] In the compounds of formula (1), Y is selected from O, S, C(CH3)2, C(phenyl)2 or The * symbol marks the C atom that is bonded to the rest of the formula (1).

[0067] Y is preferably selected from O, S and C(CH3)2.

[0068] Y is particularly preferred from O and S.

[0069] In a very particularly preferred embodiment of the main material of formula (1), Y represents O.

[0070] Therefore, the present invention also relates to an organic electroluminescent device as described above, wherein Y in the host material 1 represents O.

[0071] In the compound of formula (1), a represents 0 or 1, preferably 0.

[0072] In the compound of formula (1), b represents 0 or 1, preferably 0.

[0073] In compounds of formula (1), R, in each occurrence, is selected from CN, a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 20 carbon atoms, or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 20 carbon atoms, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, or an aralkyl or heteroarylalkyl group having 5 to 40 aromatic ring atoms. Substituent R preferably represents CN or an aryl group having 6 to 40 carbon atoms, each occurrence independently of each other. R is particularly preferably phenyl, each occurrence independently of each other.

[0074] In compounds of formula (1) as described or preferably described above, Ar1 preferably represents, in each instance, an aryl group, dibenzofuranyl, or dibenzothiophene group having 6 to 40 aromatic ring atoms. In compounds of formula (1) as described or preferably described above, Ar1 particularly preferably represents, in each case, a phenyl, triphenylimide, biphenyl, fluorenyl, naphthyl, or dibenzofuranyl group, wherein bonding with the remainder of formula (1) can occur via any desired position of the aryl group, dibenzofuranyl, or dibenzothiophene group. For example, dibenzofuranyl is preferably bonded to the remainder of formula (1) via the 1, 3, or 7 position. For example, fluorenyl is preferably bonded to the remainder of formula (1) via the 8 position. A preferred biphenyl is 1,3-biphenyl.

[0075] Particularly preferably, at least one Ar1 group represents a phenyl group and the other aromatic substituent Ar1 group represents an aryl group, dibenzofuranyl group, or dibenzothiophene group having 6 to 40 aromatic ring atoms. Very particularly preferably, the two Ar1 groups are identical. Very particularly preferably, the two Ar1 groups represent a phenyl group. Preferably, the two Ar1 groups represent a dibenzofuranyl group, wherein the bonding with the triazine is independent in each case.

[0076] In the compounds of formula (1), L is selected from linking groups L-1 to L-26, wherein linking groups L-1 to L-26 may also be substituted by one or more substituents R. Linking groups L-1 to L-26 are preferably unsubstituted or have one substituent R. Linking groups L-1 to L-26 are particularly preferably unsubstituted.

[0077] In the linking groups L-1 to L-26, the substituent R, in each occurrence, is selected from CN, a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 20 carbon atoms, or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 20 carbon atoms, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, or an aralkyl or heteroarylalkyl group having 5 to 40 aromatic ring atoms. In the linking groups L-1 to L-26, the substituent R preferably represents CN or an aryl group having 6 to 40 carbon atoms each time it appears. In the linking groups L-1 to L-26, the substituent R particularly preferably represents CN or a phenyl group each time it appears.

[0078] The host material of formula (1) having linking groups L-1 to L-26 as described or preferred above is preferably combined with the host material of formula (2) where at least one value x, x1, y, or y1 represents 1, preferably a host material represented by a compound of formula (2b) or (2c) as described below. The host material of formula (1) having linking groups L-1 to L-26 as described or preferred above is preferably combined with the host material of formula (2) where exactly one value x, x1, y, or y1 represents 1, preferably a host material represented by a compound of formula (2b) as described below.

[0079] The host material of formula (1) having linking groups L-14 to L-23 as described above (where W represents O, S or C(CH3)2 and where W is preferably O or S) is preferably combined with the host material of formula (2) having at least one value x, x1, y or y1 representing 1, preferably a host material represented by a compound of formula (2b) or (2c) as described below. The host material of formula (1) having linking groups L-14 to L-23 as described or preferably above is preferably combined with the host material of formula (2) having exactly one value x, x1, y or y1 representing 1, preferably a host material represented by a compound of formula (2b) as described below.

[0080] In the compounds of formula (1) as described or preferably described above, L is preferably selected from the linking groups L-1 to L-13 and L-24 to L-26 as described above.

[0081] The host material of formula (1) having linking groups L-1 to L-13 and L-24 to L-26 is preferably combined with the host material of formula (2) as described below, wherein x and x1 independently represent 0 or 1 each time they appear and y and y1 independently represent 0 or 1 each time they appear, and the host material of formula (2) is preferably represented by a compound of formula (2a), (2b) or (2c) as described below.

[0082] Furthermore, it is preferred that the linking group L in the main material of formula (1) is selected from linking groups L-2, L-3, L-4, L-24, L-25 and L-26.

[0083] In the compound of formula (1) as described or preferably described above, L in an alternative embodiment is preferably selected from the linking groups L-2, L-3, L-4, L-16, L-18, L-20, L-24, L-25 and L-26 as described above, wherein W represents O, S or C(CH3)2 and wherein W is preferably O or S.

[0084] Therefore, the present invention also relates to organic electroluminescent devices as described or preferably described above, wherein the linking group L in the host material 1 is selected from linking groups L-1 to L-13 and L-24 to L-26.

[0085] Therefore, the present invention also relates to organic electroluminescent devices as described or preferably described above, wherein the linking group L in the host material 1 is selected from linking groups L-2, L-3, L-4, L-16, L-18, L-20, L-24, L-25 and L-26 and W represents O, S or C(CH3)2. W is preferably O or S.

[0086] In the electroluminescent device according to the invention, examples of suitable host materials of formula (1) selected according to the invention and preferably used in combination with at least one compound of formula (2) are the structures given in Table 1 below.

[0087] Table 1:

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096] In the electroluminescent device according to the invention, compounds of formula (1) that are particularly suitable for combination with at least one compound of formula (2) are compounds 1 to 11 and 29 to 44:

[0097]

[0098]

[0099]

[0100]

[0101] The preparation of compounds of formula (1) or preferred compounds from Table 1, as well as compounds 1 to 11 and 29 to 44, is known to those skilled in the art. These compounds can be prepared by synthetic steps known to those skilled in the art, such as halogenation, preferably bromination, and subsequent organometallic coupling reactions, such as Suzuki coupling, Heck coupling, or Hartwig-Buchwald coupling. The preparation of compounds of formula (1) or preferred compounds from Table 1, as well as compounds 1 to 11 and 29 to 44, can be particularly obtained from WO2017178311, especially the synthetic examples on pages 46 and 81 to 106.

[0102] The preparation of the compound of formula (1) can be carried out according to Scheme 1 below, wherein Y, R, a, b, Ar1 and L have one of the meanings indicated or preferably indicated above.

[0103] Option 1:

[0104]

[0105] The following describes the main material 2 present in the device according to the invention and its preferred embodiments. The preferred embodiments of the main material 1 of formula (1) are also applicable to mixtures and / or formulations according to the invention.

[0106] Main material 2 is at least one compound of formula (2),

[0107]

[0108] The following applies to the symbols and markings used:

[0109] K and M are, in each case, independent of each other, aromatic ring systems having 6 to 40 aromatic ring atoms, which are unsubstituted, partially or completely deuterated, or monosubstituted by R*, provided that x and y represent 0 and x1 and y1 represent 0, or

[0110] K and M are independent of each other with X or X in each case. 1 Together they form a heteroaromatic ring system with 14 to 40 ring atoms, provided that the values ​​of x, x1, y and / or y1 represent 1;

[0111] x and x1 are 0 or 1 independently of each other in each case;

[0112] y and y1 are 0 or 1 independently of each other in each case;

[0113] X and X 1 In each case, it is a key or C(R#)2 that occurs independently of each other each time;

[0114] R 0 Each time they appear, they are independent of each other as aromatic ring systems with 6 to 18 C atoms that are either unsubstituted or partially or completely deuterated;

[0115] R# is an alkyl group, either straight-chain or branched, having 1 to 4 carbon atoms, which appears independently of each other.

[0116] c, d, e, and f are each 0 or 1 independently.

[0117] In one embodiment of the invention, as described above, the compound of formula (2) is selected for use in the device according to the invention, and is used in the light-emitting layer together with the compound of formula (1) as described or preferably described above, or together with the compounds from Table 1 or compounds 1 to 11 and 29 to 44.

[0118] In a preferred embodiment of the device according to the invention, the compound of formula (2), wherein x, y, x1, and y1 represent 0, is used as the host material 2. The compound of formula (2), wherein x, y, x1, and y1 represent 0 each time they appear, can be represented by the following formula (2a).

[0119]

[0120] Where R 0 c, d, e, and f have the meanings given above or below, and

[0121] K and M, in each case, independently represent an aromatic ring system having 6 to 40 aromatic ring atoms, which are unsubstituted or partially or completely deuterated or R* monosubstituted.

[0122] In the preferred compound of formula (2a), the sum of the labels c+d+e+f is preferably 0 or 1, and R 0 It has the meaning indicated above or below.

[0123] In compounds of formula (2) or (2a), R0 Preferably, each occurrence is an unsubstituted aromatic ring system with 6 to 18 C atoms. R 0 Preferably, each occurrence is independently of the other: phenyl, 1,3-biphenyl, 1,4-biphenyl, naphthyl, or triphenylimide. R 0 It is particularly preferred that each occurrence is an independent phenyl group.

[0124] In compounds of formula (2) or (2a), the designations c, d, e and f are particularly preferred to be 0.

[0125] In compounds of formula (2) or (2a), K and M are preferably, each time independently of each other, an aromatic ring system having 6 to 40 aromatic ring atoms, which is unsubstituted or partially deuterated or R* monosubstituted, as described above. In compounds of formula (2) or (2a), K and M are particularly preferably, each time independently of each other, a phenyl, a dibenzofuran-substituted phenyl, a dibenzothiophene-substituted phenyl, a deuterated phenyl, a 1,3-biphenyl, a 1,4-biphenyl, a terphenyl, a partially deuterated terphenyl, a tetraphenyl, a naphthyl, a fluorenyl, a 9,9-diphenylfluorenyl, a bisspirofluorenyl, or a biphenylidene.

[0126] Therefore, the present invention also relates to organic electroluminescent devices as described or preferably described above, wherein at least one compound of formula (2) corresponds to a compound of formula (2a) or a preferred embodiment of a compound of formula (2a).

[0127] In a preferred embodiment of the device according to the invention, a compound of formula (2), wherein x1 and y1 represent 0, x and y represent 0 or 1, and the sum of x and y represents 1 or 2, is used as the host material 2. A compound of formula (2), wherein x1 and y1 represent 0, x and y represent 0 or 1, and the sum of x and y represents 1 or 2, can be represented by formula (2b).

[0128]

[0129] Where X, x, y, R 0 c, d, e, and f have the meanings given above or below.

[0130] M is an aromatic ring system with 6 to 40 aromatic ring atoms, which are unsubstituted, partially or completely deuterated, or monosubstituted by R*.

[0131] K and X together form a heteroaromatic ring system with 14 to 40 ring atoms, provided that the value of x or y represents 1 or both the value of x and y represents 1.

[0132] In the preferred compound of formula (2b), the sum of the labels c+d+e+f is preferably 0 or 1, and R 0It has the meaning indicated or preferred above.

[0133] In compounds of formula (2) or (2b), the designations c, d, e and f are particularly preferred to be 0.

[0134] In compounds of formula (2) or (2b), if the sum of x+y represents 1 or 2, then K preferably forms a heteroaromatic ring system. X in compounds of formula (2) or (2b) is preferably a direct bond or C(CH3)2.

[0135] Preferred compounds of formula (2) or (2b) can be represented by formulas (2b-1) to (2b-6).

[0136]

[0137] Among them, M and R 0 c, d, e, and f have the meanings given above or preferably given above.

[0138] In compounds of formula (2), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5), or (2b-6), as described above, M is preferably an aromatic ring system having 6 to 40 aromatic ring atoms, which is unsubstituted, partially deuterated, or monosubstituted with R*. M in compounds of formula (2), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5), or (2b-6) is particularly preferably phenyl, dibenzofuran-substituted phenyl, dibenzothiophene-substituted phenyl, deuterated phenyl, 1,3-biphenyl, 1,4-biphenyl, terphenyl, partially deuterated terphenyl, tetraphenyl, naphthyl, fluorenyl, 9,9-diphenyl-fluorenyl, bisspirofluorenyl, or biphenylidene.

[0139] In compounds of formula (2b-1), (2b-2), (2b-3), (2b-4), (2b-5), or (2b-6), c, d, e, and f are preferably 0.

[0140] Therefore, the present invention also relates to organic electroluminescent devices as described or preferably described above, wherein at least one compound of formula (2) corresponds to a compound of formula (2b), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6) or a preferred embodiment of these compounds.

[0141] In a preferred embodiment of the device according to the invention, a compound of formula (2), wherein c and f represent 0 or 1, d and e represent 0 and x, x1, y and y1 represent 0 or 1 independently of each other each time they appear, but wherein the sum of x and y represents at least 1 and the sum of x1 and y1 represents at least 1, is used as the host material 2. Such compounds of formula (2) as described above can preferably be represented by the following formula (2c).

[0142]

[0143] Where X and X 1 It has the meaning given above or below.

[0144] K and M are independent of each other with X or X in each case. 1 Together they form heteroaromatic ring systems with 14 to 40 ring atoms.

[0145] x, x1, y and / or y1 represent 0 or 1, and the sum of x and y represents at least 1, and the sum of x1 and y1 represents at least 1.

[0146] In the preferred compound of formula (2c), the sum of x and y is 1 or 2 and the sum of x1 and y1 is 1. In the particularly preferred compound of formula (2c), the sum of x and y is 1 and the sum of x1 and y1 is 1.

[0147] Therefore, K and M in compounds of formula (2) or (2c) preferably form a heteroaromatic ring system. X and Xm in compounds of formula (2) or (2c) 1 The preferred choice is a direct bond or C(CH3)2.

[0148] The preferred compounds of formula (2) or (2c) can be represented by formulas (2c-1) to (2c-8).

[0149]

[0150]

[0151] Preferred compounds of formula (2c) are also compounds 46, 47, 48, 49 and 50 as described below.

[0152] Therefore, the present invention also relates to organic electroluminescent devices as described or preferably described above, wherein at least one compound of formula (2) corresponds to a compound of formula (2c), (2c-1), (2c-2), (2c-3), (2c-4), (2c-5), (2c-6), (2c-7) or (2c-8).

[0153] In a preferred embodiment of the compound of formula (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5), or (2b-6), the carbazole and the bridged carbazole are connected to each other at position 3 in each case.

[0154] In a preferred embodiment of the compound of formula (2c), the two bridged carbazoles are connected to each other at position 3 in each case.

[0155] In the electroluminescent device according to the invention, examples of suitable host materials of formulas (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) and (2c) selected and preferred according to the invention for combination with at least one compound of formula (1) are the structures shown in Table 2 below.

[0156] Table 2:

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163]

[0164] In the electroluminescent device according to the invention, compounds of formula (2) that are particularly suitable for combination with at least one compound of formula (1) are compounds 12 to 27 and 45 to 52:

[0165]

[0166]

[0167]

[0168] The preparation of compounds of formula (2) or preferred compounds of formulas (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5), and (2c), as well as compounds from Table 2 and compounds 12 to 27 and 45 to 52, is known to those skilled in the art. These compounds can be prepared by synthetic steps known to those skilled in the art, such as halogenation, preferably bromination, and subsequent organometallic coupling reactions, such as Suzuki coupling, Heck coupling, or Hartwig-Buchwald coupling. Some compounds of formula (2) are commercially available.

[0169] The main material of formula (1) above and its preferred embodiments described herein, or compounds and compounds 1 to 11 and 29 to 44 from Table 1, may be combined as needed in the device according to the invention with the main material of formulas (2), (2a), (2b), (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5), (2c), (2c-1), (2c-2), (2c-3), (2c-4), (2c-5), (2c-6), (2c-7) and (2c-8) and its preferred embodiments described herein, or compounds or compounds 12 to 27 and 45 to 52 from Table 2.

[0170] As described above, the specific combination of the main material of formula (1) and the main material of formula (2) is preferred. Preferred combinations of main materials are also described below.

[0171] The present invention also relates to mixtures comprising at least one compound of formula (1) and at least one compound of formula (2).

[0172]

[0173] The following applies to the symbols and markings used:

[0174] Y is selected from O, S, C(CH3)2, C(phenyl)2 or The * symbol marks the C atom bonded to the rest of the formula (1);

[0175] L is selected from one of the divalent linker groups L-1 to L-26.

[0176]

[0177]

[0178] The linking groups L-1 to L-26 may also be replaced by one or more substituents R;

[0179] W is O, S, or C(CH3)2; preferably O or S;

[0180] a is 0 or 1;

[0181] b is 0 or 1;

[0182] R is selected from CN each time it appears, either identically or differently, of a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 20 C atoms, of an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, of an aryloxy or heteroaromatic group having 5 to 40 aromatic ring atoms, or of an aralkyl or heteroaromatic group having 5 to 40 aromatic ring atoms;

[0183] Ar1, each time it appears, is independently of each other an aryl or heteroaryl group having 5 to 40 aromatic ring atoms, which can be substituted by one or more groups R;

[0184] K and M are, in each case, independent of each other, aromatic ring systems having 6 to 40 aromatic ring atoms, which are unsubstituted, partially or completely deuterated, or monosubstituted by R*, provided that x and y represent 0 and x1 and y1 represent 0, or

[0185] K and M are independent of each other with X or X in each case. 1 Together they form a heteroaromatic ring system with 14 to 40 ring atoms, provided that the values ​​of x, x1, y and / or y1 represent 1;

[0186] x and x1 are 0 or 1 independently of each other in each case;

[0187] y and y1 are 0 or 1 independently of each other in each case;

[0188] X and X 1 In each case, it is a key or C(R#)2 that occurs independently of each other each time;

[0189] R 0 Each time they appear, they are independent of each other as aromatic ring systems with 6 to 18 C atoms that are either unsubstituted or partially or completely deuterated;

[0190] R* is dibenzofuranyl or dibenzothiophenylyl;

[0191] R# is an alkyl group, either straight-chain or branched, having 1 to 4 carbon atoms, which appears independently of each other; and

[0192] c, d, e, and f are each 0 or 1 independently.

[0193] The statements regarding the main materials of formulas (1) and (2), their preferred embodiments, and combinations thereof also apply accordingly to mixtures according to the invention.

[0194] A particularly preferred mixture of the body material of formula (1) and the body material of formula (2) for use in the device according to the invention is obtained by combining compounds 1 to 11 and 29 to 44 with compounds from Table 2.

[0195] A very particularly preferred mixture of the body material of formula (1) and the body material of formula (2) for use in the device according to the invention is obtained by combining compounds 1 to 11 and 29 to 44 with compounds 12 to 27 and 45 to 52 as shown in Table 3 below.

[0196] Table 3:

[0197]

[0198]

[0199]

[0200]

[0201]

[0202]

[0203]

[0204] Based on the entire mixture or the entire composition of the light-emitting layer, the concentration of the electron transport host material of formula (1) as described or preferably above in the mixture according to the invention or in the light-emitting layer of the device according to the invention is in the range of 5 wt% to 90 wt%, preferably in the range of 10 wt% to 85 wt%, more preferably in the range of 20 wt% to 85 wt%, even more preferably in the range of 30 wt% to 80 wt%, very particularly preferably in the range of 20 wt% to 60 wt%, and most preferably in the range of 30 wt% to 50 wt%.

[0205] Based on the entire mixture or the entire composition of the light-emitting layer, the concentration of the hole transport host material as described above or as preferably described in formula (2) in the mixture according to the invention or in the light-emitting layer of the device according to the invention is in the range of 10 wt% to 95 wt%, preferably in the range of 15 wt% to 90 wt%, more preferably in the range of 15 wt% to 80 wt%, even more preferably in the range of 20 wt% to 70 wt%, very particularly preferably in the range of 40 wt% to 80 wt%, and most preferably in the range of 50 wt% to 70 wt%.

[0206] The present invention also relates to a mixture that, in addition to the main materials 1 and 2 as described or preferably described above, particularly mixtures M1 to M648, further comprises at least a phosphorescent material.

[0207] The present invention also relates to organic electroluminescent devices as described or preferably described above, wherein the light-emitting layer, in addition to comprising the host materials 1 and 2 as described or preferably described above, particularly material combinations M1 to M648, also comprises at least a phosphorescent material.

[0208] The term phosphorescent emitter generally encompasses compounds that emit light through spin-forbidden transitions from excited states with higher spin multiplicity (i.e., spin > 1), such as from triplet states or states with even higher spin quantum numbers (e.g., quintet states). This is preferably considered to refer to transitions from triplet states.

[0209] Suitable phosphorescent emitters (= triplet emitters) are particularly compounds that emit light upon appropriate excitation, preferably in the visible region, and also contain at least one atom with an atomic number greater than 20, preferably greater than 38 and less than 84, particularly preferably greater than 56 and less than 80, especially a metal having that atomic number. The phosphorescent emitters used are preferably compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold, or europium, especially compounds containing iridium or platinum. For the purposes of this invention, all luminescent compounds containing the above-mentioned metals are considered phosphorescent emitters.

[0210] Generally, all phosphorescent complexes known to those skilled in the art in the field of organic electroluminescent devices are suitable according to existing technologies for phosphorescent OLEDs.

[0211] Examples of the above-mentioned luminophores are provided by applications WO 2016 / 015815, WO 00 / 70655, WO 2001 / 41512, WO2002 / 02714, WO 2002 / 15645, EP 1191613, EP 1191612, EP 1191614, WO 05 / 033244, WO 05 / 019373、US 2005 / 0258742、WO 2009 / 146770、WO 2010 / 015307、WO 2010 / 031485、WO 2010 / 054731、WO 2010 / 054728、WO 2010 / 086089、WO 2010 / 099852、WO 2010 / 102709, WO 2011 / 032626, WO 2011 / 066898, WO 2011 / 157339, WO 2012 / 007086, WO 2014 / 008982, WO 2014 / 023377, WO 2014 / 094961, WO 2014 / 094960、WO 2015 / 036074、WO 2015 / 104045、WO 2015 / 117718、WO 2016 / 015815、WO 2016 / 124304、WO 2017 / 032439、WO 2015 / 036074、WO 2015 / 117718 and WO Revealed on 2016 / 015815.

[0212] According to the present invention, the preferred phosphorescent emitter conforms to formula (3).

[0213]

[0214] The symbols and notations in equation (3) have the following meanings:

[0215] When n+m is 3, n is 1 or 2, and m is 2 or 1.

[0216] X is N or CR.

[0217] R is H, D, or a branched or straight-chain alkyl group having 1 to 10 C atoms, or a partially or fully deuterated branched or straight-chain alkyl group having 1 to 10 C atoms, or a cycloalkyl group having 4 to 7 C atoms, said group being partially or fully deuterated.

[0218] Therefore, the present invention also relates to an organic electroluminescent device as described or preferably described above, characterized in that the light-emitting layer, in addition to the host materials 1 and 2, also contains at least one phosphorescent material conforming to formula (3) as described above.

[0219] In the light emitter of formula (3), n is preferably 1 and m is preferably 2.

[0220] In the luminescent body of formula (3), preferably one X is selected from N and the other X represents CR.

[0221] In the light emitter of formula (3), at least one R is preferably not H. In the light emitter of formula (3), preferably two Rs are not H and have one of the additional meanings pointed out above for the light emitter of formula (3).

[0222] Preferred examples of phosphorescent luminescent materials are shown in Table 4 below.

[0223] Table 4:

[0224]

[0225]

[0226]

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[0236]

[0237]

[0238]

[0239]

[0240]

[0241]

[0242] Preferred examples of phosphorescent multi-legged luminescent organisms are shown in Table 5 below.

[0243] Table 5:

[0244]

[0245]

[0246]

[0247]

[0248] In the mixtures according to the invention or in the light-emitting layer of the device according to the invention, each of the following mixtures is preferably combined with a compound of formula (3) or a compound from Table 4 or Table 5: M1, M2, M3, M4, M5, M6, M7, M8, M9, M10, M11, M12, M13, M14, M15, M16, M17, M18, M19, M20, M21, M22, M23, M24, M25, M26, M27, M28, M29, M30, M31, M32, M33, M34, M35, M36, M37, M38, M39, M40, M41, M42, M43, M44, M45, M46, M47, M48, M49, M50, M51, M52, M53, M54, M55, M56, M57, M58, M59, M60, M61, M62, M63, M64, M65, M6 6. M67, M68, M69, M70, M71, M72, M73, M74, M75, M76, M77, M78, M79, M80, M81, M 82, M83, M84, M85, M86, M87, M88, M89, M90, M91, M92, M93, M94, M95, M96, M97 , M98, M99, M100, M101, M102, M103, M104, M105, M106, M107, M108, M109, M110 , M111, M112, M113, M114, M115, M116, M117, M118, M119, M120, M121, M122, M 123, M124, M125, M126, M127, M128, M129, M130, M131, M132, M133, M134, M135 , M136, M137, M138, M139, M140, M141, M142, M143, M144, M145, M146, M147, M 148, M149, M150, M151, M152, M153, M154, M155, M156, M157, M158, M159, M160 , M161, M162, M163, M164, M165, M166, M167, M168, M169, M170, M171, M172, M 173, M174, M175, M176, M177, M178, M179, M180, M181, M182, M183, M184, M185 , M186, M187, M188, M189, M190, M191, M192, M193, M194, M195, M196, M197, M1 98. M199, M200, M201, M202, M203, M204, M205, M206, M207, M208, M209, M210,M211, M212, M213, M214, M215, M216, M217, M218, M219, M220, M221, M222, M223, M224, M225, M226, M227, M228, M229, M230, M231, M232, M233, M234, M235 M236, M237, M238, M239, M240, M241, M242, M243, M244, M245, M246, M247, M248, M249, M250, M251, M252, M253, M254, M255, M256, M257, M258, M259, M260 M261, M262, M263, M264, M265, M266, M267, M268, M269, M270, M271, M272, M273, M274, M275, M276, M277, M278, M279, M280, M281, M282, M283, M284, M285 M286, M287, M288, M289, M290, M291, M292, M293, M294, M295, M296, M297, M298, M299, M300, M301, M302, M303, M304, M305, M306, M307, M308, M309, M310 M311, M312, M313, M314, M315, M316, M317, M318, M319, M320, M321, M322, M323, M324, M325, M326, M327, M328, M329, M330, M331, M332, M333, M334, M335 M336, M337, M338, M339, M340, M341, M342, M343, M344, M345, M346, M347, M348, M349, M350, M351, M352, M353, M354, M355, M356, M357, M358, M359, M360 M361, M362, M363, M364, M365, M366, M367, M368, M369, M370, M371, M372, M373, M374, M375, M376, M377, M378, M379, M380, M381, M382, M383, M384, M385 M386, M387, M388, M389, M390, M391, M392, M393, M394, M395, M396, M397, M398, M399, M400, M401, M402, M403, M404, M405, M406, M407, M408, M409, M410M411、M412、M413、M414、M415、M416、M417、M418、M419、M420、M421、M422、M423、M424、M425、M426、M427、M428、M429、M430、M431、M432、M433、M434、M435、M436、M437、M438、M439、M440、M441、M442、M443、M444、M445、M446、M447、M448、M449、M450、M451、M452、M453、M454、M455、M456、M457、M458、M459、M460、M461、M462、M463、M464、M465、M466、M467、M468、M469、M470、M471、M472、M473、M474、M475、M476、M477、M478、M479、M480、M481、M482、M483、M484、M485、M486、M487、M488、M489、M490、M491、M492、M493、M494、M495、M496、M497、M498、M499、M500、M501、M502、M503、M504、M505、M506、M507、M508、M509、M510、M511、M512、M513、M514、M515、M516、M517、M518、M519、M520、M521、M522、M523、M524、M525、M526、M527、M528、M529、M530、M531、M532、M533、M534、M535、M536、M537、M538、M539、M540、M541、M542、M543、M544、M545、M546、M547、M548、M549、M550、M551、M552、M553、M554、M555、M556、M557、M558、M559、M560、M561、M562、M563、M564、M565、M566、M567、M568、M569、M570、M571、M572、M573、M574、M575、M576、M577、M578、M579、M580、M581、M582、M583、M584、M585、M586、M587、M588、M589、M590、M591、M592、M593、M594、M595、M596、M597、M598、M599、M600、M601、M602、M603、M604、M605、M606、M607、M608、M609、M610、M611, M612, M613, M614, M615, M616, M617, M618, M619, M620, M621, M622, M623, M624, M625, M626, M627, M628, M629, M630, M631, M632, M633, M634, M635, M636, M637, M638, M639, M640, M641, M642, M643, M644, M645, M646, M647, M648. ,

[0249] The light-emitting layer in the organic electroluminescent device according to the present invention, which contains at least one phosphorescent light-emitting element, is preferably an infrared, yellow, orange, red, green, blue or ultraviolet light-emitting layer, particularly preferably a yellow or green light-emitting layer, and very particularly preferably a green light-emitting layer.

[0250] Here, the yellow emitting layer is considered to be a layer with a maximum photoluminescence value in the range of 540 to 570 nm. The orange emitting layer is considered to be a layer with a maximum photoluminescence value in the range of 570 to 600 nm. The red emitting layer is considered to be a layer with a maximum photoluminescence value in the range of 600 to 750 nm. The green emitting layer is considered to be a layer with a maximum photoluminescence value in the range of 490 to 540 nm. The blue emitting layer is considered to be a layer with a maximum photoluminescence value in the range of 440 to 490 nm. The photoluminescence of the layers is determined here by measuring the photoluminescence spectrum of a layer with a thickness of 50 nm at room temperature, wherein the layer comprises a combination of a host material according to formulas (1) and (2) of the present invention and a corresponding emitting body.

[0251] For example, the photoluminescence spectrum of the recording layer can be recorded using a commercially available photoluminescence spectrometer.

[0252] The photoluminescence spectrum of the selected luminescent material is typically in the range of 10. -5 The measurement is performed in an oxygen-free solution of molar concentration at room temperature, and any solvent is suitable as long as the selected luminescent material is dissolved in it at the stated concentration. Particularly suitable solvents are typically toluene or 2-methyl-THF, as well as dichloromethane. The measurement is performed using a commercially available photoluminescence spectrometer. The triplet energy T1 (in eV) is determined from the photoluminescence spectrum of the luminescent material. First, the peak maximum value Plmax. (in nm) of the photoluminescence spectrum is determined. Then, the peak maximum value Plmax. (in nm) is converted to eV using the following formula: E(T1 in eV) = 1240 / E(T1 in nm) = 1240 / Plmax. (nm).

[0253] Therefore, the preferred phosphorescent emitter is an infrared emitter with a triplet energy T1 preferably of about 1.9 eV to about 1.0 eV.

[0254] Therefore, the preferred phosphorescent emitter is a red emitter, preferably having formula (3) or from Table 4 or Table 5, with a triplet energy T1 preferably from about 2.1 eV to about 1.9 eV.

[0255] Therefore, the preferred phosphorescent emitter is a yellow emitter, preferably having formula (3) or from Table 4 or Table 5, with a triplet energy T1 preferably of about 2.3 eV to about 2.1 eV.

[0256] Therefore, the preferred phosphorescent emitter is a green emitter, preferably having formula (3) or from Table 4 or Table 5, with a triplet energy T1 preferably of about 2.5 eV to about 2.3 eV.

[0257] Therefore, the preferred phosphorescent emitter is a blue emitter, preferably having formula (3) or from Table 4 or Table 5, with a triplet energy T1 preferably from about 3.1 eV to about 2.5 eV.

[0258] Therefore, the preferred phosphorescent emitter is an ultraviolet emitter, preferably having formula (3) or from Table 4 or Table 5, with a triplet energy T1 preferably from about 4.0 eV to about 3.1 eV.

[0259] Therefore, the particularly preferred phosphorescent emitters are green or yellow emitters, preferably having formula (3) or from Table 4 or Table 5 as described above.

[0260] Therefore, the most particularly preferred phosphorescent emitter is a green emitter, preferably having formula (3) or from Table 4 or Table 5, with a triplet energy T1 preferably of about 2.5 eV to about 2.3 eV.

[0261] As described above, green light emitters having formula (3) or from Table 4 or Table 5 are particularly preferred for use in the compositions or light-emitting layers according to the invention.

[0262] The light-emitting layer of the device according to the present invention may further include a fluorescent light emitter.

[0263] Preferred fluorescent emitters are selected from the arylamine class. In the context of this invention, arylamines or aromatic amines are considered to be compounds containing three substituted or unsubstituted aromatic or heteroaromatic ring systems directly bonded to nitrogen. At least one of these aromatic or heteroaromatic ring systems is preferably a fused ring system, particularly preferably having at least 14 aromatic ring atoms. Preferred examples are aromatic anthraceneamines, aromatic anthracene diamines, aromatic pyreneamines, aromatic pyrene diamines, aromatic pyrine amines, or aromatic pyrine diamines. Aromatic anthraceneamines are considered to be compounds in which one diarylamino group is directly bonded to an anthracene group, preferably at the 9-position. Aromatic anthracene diamines are considered to be compounds in which two diarylamino groups are directly bonded to an anthracene group, preferably at the 9- and 10-positions. Aromatic pyreneamines, pyrene diamines, pyrine amines, and pyrine diamines are defined in a similar manner, wherein the diarylamino group is preferably bonded to pyrene at the 1-position or at the 1- and 6-positions. Other preferred phosphors are indenefluoreneamine or indenefluorenediamine, for example according to WO 2006 / 108497 or WO 2006 / 122630; benzo[a]indenefluoreneamine or benzo[a]indenefluorenediamine, for example according to WO 2008 / 006449; and dibenzo[a]indenefluoreneamine or dibenzo[a]indenefluorenediamine, for example according to WO 2007 / 140847; and indenefluorene derivatives containing fused aryl groups, disclosed in WO 2010 / 012328.

[0264] In another preferred embodiment of the invention, at least one light-emitting layer of the organic electroluminescent device may contain, in addition to the host materials 1 and 2 as described above or preferably, another host material or matrix material, a so-called hybrid matrix system. The hybrid matrix system preferably contains three or four different matrix materials, particularly preferably three different matrix materials (i.e., another matrix component besides host materials 1 and 2 as described above). Particularly suitable matrix materials that can be combined as matrix components of the hybrid matrix system are selected from wide-bandgap materials, bipolar host materials, electron transport materials (ETM), and hole transport materials (HTM).

[0265] Wide bandgap material as used herein is considered to be a material in the sense of the disclosure in US 7,294,849, characterized by a bandgap of at least 3.5 eV, wherein the bandgap is considered to be the interval between the HOMO and LOMO energies of the material.

[0266] More precise details regarding the hybrid matrix system are given in application WO 2010 / 108579. Particularly suitable matrix materials are selected from those indicated below as preferred matrix materials for phosphorescent emitters or preferred matrix materials for fluorescent emitters, depending on the type of emitter used. These particularly suitable matrix materials can be combined with host materials 1 and 2 as described or preferably above as matrix components of a hybrid matrix system in a phosphorescent or fluorescent organic light-emitting device. The hybrid matrix system is preferably optimized for emitters of formula (3) or those from Tables 4 or 5.

[0267] In the device according to the invention as described above, suitable other host materials for the phosphor are preferably substances of various classes, and in addition to host materials 1 and 2, particularly preferably a combination of host materials selected from M1 to M648. Preferred other host materials are selected from the following categories: oligomeric aromatic derivatives (e.g., 2,2',7,7'-tetraphenylspirodifluorene or dinafylanthracene according to EP 676461), particularly oligomeric aromatic derivatives containing fused aromatic groups, oligomeric aromatic vinylides (e.g., DVBBi or spiro-DPVBBi according to EP 676461), multi-legged metal complexes (e.g., according to WO 2004 / 081017), hole-conducting compounds (e.g., according to WO 2004 / 058911), electron-conducting compounds, particularly ketones, phosphine oxides, sulfoxides, etc. (e.g., according to WO 2005 / 084081 and WO 2005 / 084082), transisomers (e.g., according to WO 2006 / 048268), boric acid derivatives (e.g., according to WO 2006 / 117052) or benzanthracene (e.g., according to WO 2006 / 117052). 2008 / 145239). Particularly preferred matrix materials are selected from the class of oligomeric arylene groups: those comprising naphthalene, anthracene, benzanthracene and / or pyrene or transisomers of these compounds, oligomeric arylene vinylides, ketones, phosphine oxides, and sulfoxides. Very particularly preferred matrix materials are selected from the class of oligomeric arylene groups: those comprising anthracene, benzanthracene, benzo[a]phenanthrene and / or pyrene or transisomers of these compounds. Oligomeric arylene groups in the sense of this invention are intended to be considered as compounds in which at least three aryl or arylene groups are bonded to each other.

[0268] In addition to the main materials 1 and 2, other suitable matrix materials preferably used in the device according to the invention as described above, which particularly preferably include a combination of main materials selected from M1 to M648 as described above, are compounds of the following categories: aromatic amines, especially triarylamines, for example according to US 2005 / 0069729; carbazole derivatives (e.g., CBP, N,N-biscarbazole biphenyl) or compounds, according to WO 2005 / 039246, US 2005 / 0069729, JP2004 / 288381, EP 1205527 or WO 2008 / 086851; bridged carbazole derivatives, for example according to WO 2011 / 088877 and WO 2011 / 128017; indobenzocarbazole derivatives, for example according to WO 2010 / 136109 and WO 2011 / 000455; azirconazole derivatives, such as those according to EP 1617710, EP 1617711, EP 1731584, JP 2005 / 347160; indole-carbazole derivatives, such as those according to WO 2007 / 063754 or WO 2008 / 056746; ketones, such as those according to WO 2004 / 093207 or WO 2010 / 006680; phosphine oxides, sulfoxides and sulfones, such as those according to WO 2005 / 003253; oligophenylene oxides, bipolar matrix materials, such as those according to WO 2007 / 137725; silanes, such as those according to WO 2005 / 111172; borazonicyclopentanes or borate esters, such as those according to WO 2006 / 117052; triazine derivatives, such as those according to WO2010 / 015306, WO 2007 / 063754 or WO 2008 / 056746; zinc complexes, such as those according to EP 652273 or WO2009 / 062578; aluminum complexes, such as BAlq; silicon diazacyclopentane and silicon tetraazacyclopentane derivatives, such as those according to WO 2010 / 054729; phosphorus diazacyclopentane derivatives, such as those according to WO 2010 / 054730; and aluminum complexes, such as BAlQ.

[0269] According to one embodiment of the invention, the mixture contains no other components, i.e., functional materials, besides the electron transport host material of formula (1) and the hole transport host material of formula (2). These are also material mixtures used to manufacture the light-emitting layer. These mixtures are also called premixed systems, which serve as the sole material source during the vapor deposition of the host material of the light-emitting layer and have a constant mixing ratio during vapor deposition. This enables vapor deposition of a layer with a uniform distribution of components in a simple and rapid manner without the need for precise control of multiple material sources.

[0270] According to an alternative embodiment of the invention, the mixture, in addition to comprising the electron transport host material of formula (1) and the hole transport host material of formula (2), also comprises the phosphorescent emitter as described above. As mentioned above, given a suitable mixing ratio during vapor deposition, the mixture can also be used as the sole material source.

[0271] Therefore, the components or constituent parts of the light-emitting layer of the device according to the invention can be processed by vapor deposition or from solution. For this purpose, the host materials 1 and 2 as described or preferably above are optionally combined with the materials of the phosphorescent emitter as described or preferably above in a formulation containing at least one solvent. These formulations can be, for example, solutions, dispersions, or emulsions. For this purpose, a mixture of two or more solvents may preferably be used.

[0272] Therefore, the present invention also relates to a formulation comprising, according to the invention, a mixture of the main materials 1 and 2 as described above, optionally combined with a phosphorescent emitter as described or preferably described above, and at least one solvent.

[0273] Suitable and preferred solvents include, for example, toluene, anisole, o-xylene, m-xylene or p-xylene, methyl benzoate, mesitylene, naphthol, o-dimethoxybenzene, THF, methyl-THF, THP, chlorobenzene, and dimethylbenzene. Alkane, phenoxytoluene, especially 3-phenoxytoluene, (-)-fonone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, α-terpineol, benzothiazole, butyl benzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, naphthane, dodecylbenzene Ethyl benzoate, indane, methyl benzoate, NMP, p-isopropyltoluene, phenethyl ether, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, hexamethylindane, or mixtures of these solvents.

[0274] The formulation described herein may also contain at least one additional organic or inorganic compound, which is also used in the light-emitting layer of the device according to the invention, particularly additional light-emitting compounds and / or additional matrix materials. Suitable light-emitting compounds and additional matrix materials have been pointed out above.

[0275] Based on the entire composition comprising a luminescent material and a matrix material, the luminescent layer in the device of the present invention according to the preferred embodiment and the luminescent compound preferably comprises a matrix material comprising at least one compound of formula (1) and at least one compound of formula (2) according to the preferred embodiment, between 99.9 vol% and 1 vol%, more preferably between 99 vol% and 10 vol%, particularly preferably between 98 vol% and 60 vol%, and very particularly preferably between 97 vol% and 80 vol%. Accordingly, based on the entire composition of the luminescent layer consisting of a luminescent material and a matrix material, the luminescent layer in the device according to the present invention preferably comprises a luminescent material between 0.1 vol% and 99 vol%, more preferably between 1 vol% and 90 vol%, particularly preferably between 2 vol% and 40 vol%, and very particularly preferably between 3 vol% and 20 vol%. If the compound is processed from a solution, it is preferable to use the corresponding weight % instead of the above-mentioned volume % amount.

[0276] According to the preferred embodiment and the luminescent compound, the luminescent layer in the device of the present invention preferably comprises a matrix material of formula (1) and a matrix material of formula (2) with a volume percentage between 3:1 and 1:3, preferably between 1:2.5 and 1:1, and particularly preferably between 1:2 and 1:1. If the compound is processed from a solution, it is preferable to use the corresponding weight % ratio instead of the above volume % ratio.

[0277] The preferred layer order in the organic electroluminescent device according to the present invention is as follows:

[0278] Anode / hole injection layer / hole transport layer / light emission layer / electron transport layer / electron injection layer / cathode.

[0279] The layer order is a preferred order.

[0280] It should be noted again here that not all of the aforementioned layers are required, and / or other layers may exist.

[0281] The organic electroluminescent device according to the present invention may include multiple light-emitting layers. At least one light-emitting layer, as described above, is a light-emitting layer according to the present invention, comprising at least one compound of formula (1) as host material 1 and at least one compound of formula (2) as host material 2. In this case, these light-emitting layers particularly preferably have a total of multiple emission peaks between 380 nm and 750 nm, thereby producing white light overall, i.e., using various light-emitting compounds capable of fluorescence or phosphorescence and emitting blue, yellow, orange, or red light in the light-emitting layers. A three-layer system is particularly preferred, i.e., a system having three light-emitting layers, wherein the three layers exhibit blue, green, and orange or red light emission (for the basic structure, see, for example, WO2005 / 011013). It should be noted that for the generation of white light, it may also be suitable to use a single light-emitting compound that emits light over a wide wavelength range instead of multiple colored light-emitting compounds.

[0282] Suitable charge transport materials that can be used in the hole injection or hole transport layer or electron blocking layer or electron transport layer of the organic electroluminescent device according to the present invention are, for example, compounds disclosed in Y. Shirota et al., Chem. Rev. 2007, 107(4), 953-1010 or other materials used in these layers according to the prior art.

[0283] Materials that can be used in electron transport layers are those used as electron transport materials in electron transport layers according to existing technologies. Particularly suitable are aluminum complexes such as Alq3, zirconium complexes such as Zrq4, benzimidazole derivatives, triazine derivatives, pyrimidine derivatives, pyridine derivatives, pyrazine derivatives, quinoxaline derivatives, and quinoline derivatives. Diazole derivatives, aromatic ketones, lactams, boranes, phosphazacyclopentane derivatives, and phosphine oxide derivatives. Other suitable materials are derivatives of the above compounds, such as those disclosed in JP 2000 / 053957, WO 2003 / 060956, WO 2004 / 028217, WO 2004 / 080975, and WO2010 / 072300.

[0284] Preferred hole transport materials, particularly those suitable for hole transport, hole injection, or electron blocking layers, include, for example, indene-fluoreneamine derivatives (e.g., according to WO 06 / 122630 or WO 06 / 100896), amine derivatives disclosed in EP 1661888, hexaazatriphenylide derivatives (e.g., according to WO 01 / 049806), amine derivatives containing fused aromatic rings (e.g., according to US 5,061,569), amine derivatives disclosed in WO 95 / 09147, monobenzo[a]indenefluoreneamine (e.g., according to WO 08 / 006449), dibenzo[a]indenefluoreneamine (e.g., according to WO 07 / 140847), spirodifluoreneamine (e.g., according to WO 2012 / 034627 or the unpublished EP 12000929.5), and fluoreneamine (e.g., according to WO 06 / 122630 or WO 06 / 100896), etc. WO 2014 / 015937, WO 2014 / 015938 and WO 2014 / 015935), spirodibenzopyranamine (e.g. according to WO 2013 / 083216) and dihydroacridine derivatives (e.g. according to WO 2012 / 150001).

[0285] Suitable cathodes for the devices according to the invention are metals, metal alloys, or multilayer structures with low work functions, comprising a variety of metals such as alkaline earth metals, alkali metals, group metals, or lanthanides (e.g., Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). Alloys comprising alkali metals or alkaline earth metals and silver are also suitable, for example, alloys comprising magnesium and silver. In the case of multilayer structures, other metals with relatively high work functions, such as Ag or Al, may also be used, in which case combinations of metals such as Ca / Ag, Mg / Ag, or Ba / Ag are typically used. It is also preferable to introduce a thin interlayer of material with a high dielectric constant between the metal cathode and the organic semiconductor. Suitable for this purpose are, for example, alkali metal fluorides or alkaline earth metal fluorides, but also the corresponding oxides or carbonates (e.g., LiF, Li₂O, BaF₂, MgO, NaF, CsF, Cs₂CO₃, etc.). Furthermore, lithium hydroxyquinoline (LiQ) may also be used for this purpose. The thickness of this layer is preferably between 0.5 nm and 5 nm.

[0286] Preferably, the anode comprises a material with a high work function. More preferably, the anode has a work function greater than 4.5 eV relative to vacuum. On one hand, metals with high redox potentials, such as Ag, Pt, or Au, are suitable for this purpose. On the other hand, metal / metal oxide electrodes (e.g., Al / Ni / NiO) are also preferred. x Al / PtO xFor some applications, at least one electrode must be transparent or partially transparent to facilitate the irradiation of organic materials (organic solar cells) or the coupling and output of light (OLEDs, O-lasers). The preferred anode material here is a conductive mixed metal oxide. Indium tin oxide (ITO) or indium zinc oxide (IZO) is particularly preferred. Furthermore, conductive doped organic materials, especially conductive doped polymers, are preferred. Additionally, the anode may consist of multiple layers, for example, an inner layer of ITO and an outer layer of metal oxide (preferably tungsten oxide, molybdenum oxide, or vanadium oxide).

[0287] During production, the organic electroluminescent device according to the invention is appropriately structured (depending on the application), provided with contact, and finally sealed, because the lifespan of the device according to the invention is shortened in the presence of water and / or air.

[0288] The production of the device according to the invention is not limited herein. One or more organic layers, including a light-emitting layer, can be applied by a sublimation process, wherein the material is deposited in a vacuum sublimation unit at a temperature of less than 10 °C. -5 millibars, preferably less than 10 -6 An initial pressure of millibars is applied. However, the initial pressure can also be lower, for example, less than 10. -7 millibar.

[0289] A preferred feature of the organic electroluminescent device according to the invention is that one or more layers are applied by OVPD (organic vapor deposition) or by means of carrier gas sublimation, wherein the layers are between 10... -5 The material is applied at a pressure between millibar and 1 bar. A specific example of this method is OVJP (Organic Vapor Jetting), in which the material is applied directly through a nozzle and thus structured (e.g., MS Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

[0290] A further preferred feature of the organic electroluminescent device according to the invention is that one or more organic layers comprising the composition according to the invention are produced from solution, for example by spin coating, or by any desired printing method such as screen printing, flexographic printing, nozzle printing, or offset printing, but particularly preferably by LITI (photoinduced thermal imaging, thermal transfer) or inkjet printing. For this purpose, soluble host materials 1 and 2 and a phosphorescent emitter are required. The advantage of processing from solution is, for example, that the light-emitting layer can be applied in a very simple and inexpensive manner. The technique is particularly suitable for the large-scale production of organic electroluminescent devices.

[0291] A hybrid approach is also possible, in which, for example, one or more layers are applied from a solution, and one or more additional layers are applied by vapor deposition.

[0292] These methods are generally known to those skilled in the art and can be applied to organic electroluminescent devices.

[0293] Therefore, the present invention also relates to a method for producing an organic electroluminescent device according to the invention as described or preferably above, characterized in that the light-emitting layer is applied by vapor deposition, particularly by a sublimation process and / or by an OVPD (organic vapor deposition) method and / or by means of a carrier gas sublimation, or applied from a solution, particularly by spin coating or by a printing process.

[0294] In the case of production via vapor deposition, there are essentially two possibilities regarding how the luminescent layer according to the invention can be applied or vapor-deposited onto any desired substrate or prior layer. On the one hand, the materials used can each exist in a single material source and eventually evaporate from each of the various material sources (“co-evaporation”). On the other hand, the various materials can be premixed (premixed system) and the mixture can be presented in a single material source, eventually evaporating from that material source (“premixed evaporation”). This makes it possible to achieve vapor deposition of a luminescent layer with a uniform distribution of components in a simple and rapid manner without the need for precise control of multiple material sources.

[0295] Therefore, the present invention also relates to a method for manufacturing a device according to the invention, characterized in that at least one compound of formula (1) as described above or preferably described above and at least one compound of formula (2) as described above or preferably described above are continuously or simultaneously deposited from at least two material sources from the vapor phase, optionally deposited together with at least one phosphorescent material as described above or preferably described above, and forming a light-emitting layer.

[0296] In a preferred embodiment of the invention, the luminescent layer is applied by vapor deposition, wherein the components of the composition are premixed and evaporated from a single material source.

[0297] Therefore, the present invention also relates to a method for manufacturing a device according to the present invention, characterized in that at least one compound of formula (1) and at least one compound of formula (2) are continuously or simultaneously deposited from the vapor phase as a mixture with at least one phosphorescent emitter to form an emitting layer.

[0298] The present invention also relates to a method for manufacturing a device according to the invention as described above or preferably, characterized in that at least one compound of formula (1) and at least one compound of formula (2) as described above or preferably, are applied from a solution together with at least one phosphorescent material to form a light-emitting layer.

[0299] The outstanding features of the device according to the present invention compared with the prior art are the following surprising advantages:

[0300] As described above, the combination of materials used in the main materials 1 and 2 specifically leads to an increase in device lifespan.

[0301] As can be seen from the examples given below, by comparing the data of the OLED with the data of the combination from the prior art, it can be observed that, regardless of the emitter concentration, the combination of matrix materials in the EML according to the present invention results in an increase in device lifetime of about 30% to 70%.

[0302] It should be noted that variations of the embodiments described in this invention are all within the scope of this invention. Unless explicitly excluded, each feature disclosed in this invention can be replaced by alternative features providing the same, equivalent, or similar purpose. Therefore, unless otherwise stated, each feature disclosed in this invention should be considered an instance of a class series or as an equivalent or similar feature.

[0303] All features of this invention can be combined with each other in any way, unless certain features and / or steps are mutually exclusive. This is especially true for preferred features of the invention. Similarly, features that are not necessarily combined can be used alone (rather than in combination).

[0304] The technical teachings disclosed in this invention can be refined and combined with other examples.

[0305] The invention is explained in more detail by way of the following embodiments, but is not intended to limit the invention thereon.

[0306] General method:

[0307] In all quantum chemical calculations, the Gaussian16 (Revision B.01) software package was used. The neutral singlet ground state was optimized to the B3LYP / 6-31G(d) level. At the B3LYP / 6-31G(d) level, the HOMO and LUMO values ​​were determined for the ground state energy optimized using B3LYP / 6-31G(d). Then, TD-DFT singlet and triplet excitations (vertical excitations) were calculated using the same method (B3LYP / 6-31G(d)), and the optimized ground state geometry was computed. Standard settings for SCF and gradient convergence were used.

[0308] The energy calculations yield the HOMO (Homo Optica Molar) as the last orbital occupied by two electrons (αocc. eigenvalue) and the LUMO (Lower Unoccupied Orbital) as the first unoccupied orbital (αvirt. eigenvalue), expressed in Hartree, where HEh and LEh represent the HOMO and LUMO energies (in Hartree, respectively). The HOMO and LUMO values ​​(in electron volts) are thus determined, calibrated using cyclic voltammetry, as follows:

[0309] HOMOcorr=0.90603*HOMO-0.84836

[0310] LUMOcorr=0.99687*LUMO-0.72445.

[0311] The triplet energy level T1 of a material is defined as the relative excitation energy (in eV) of the lowest energy triplet state derived from quantum chemical energy calculations.

[0312] The singlet level S1 is defined as the relative excitation energy (in eV) of the singlet state with the second lowest energy, which is generated by quantum chemical energy calculations.

[0313] The singlet state with the lowest energy is called S0.

[0314] The method described herein is independent of the software package used and always yields the same results. Examples of commonly used programs for this purpose are "Gaussian09" (Gaussian Corporation) and Q-Chem 4.1 (Q-Chem Corporation). In this application, the energy is calculated using the "Gaussian16, Revision B.01" software package.

[0315] Example 1: OLED Production

[0316] The use of the material combination according to the invention in OLEDs, compared with material combinations from the prior art, is presented in the following embodiments V1 to Ex28 (see Tables 6 and 7).

[0317] Pretreatment of Examples V1 to Ex28: Glass plates coated with 50 nm thick structured ITO (indium tin oxide) were first treated with oxygen plasma, followed by argon plasma, before coating. These plasma-treated glass plates formed the substrate for applying the OLED.

[0318] The OLED essentially has the following layer structure: substrate / hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / emitting layer (EML) / optional hole blocking layer (HBL) / electron transport layer (ETL) / optional electron injection layer (EIL), and finally a cathode. The cathode is formed of an aluminum layer with a thickness of 100 nm. The precise structure of the OLED is shown in Table 6. The materials required to produce the OLED are shown in Table 8. The device data for the OLED are listed in Table 7.

[0319] Examples V1, V2, and V3 are comparative examples of hole transport entities according to prior art WO2017 / 178311. Examples Ex1, Ex2, and Ex3 use corresponding material combinations according to the present invention in EML.

[0320] Examples V4 and V5 are comparative examples of the OLED of the present invention according to Example Ex4, while Examples V6 and V7 are comparative examples of the OLED of the present invention according to Example Ex5, having symmetrically substituted electron transport host materials according to the prior art. Compound VG1 is derived from, for example, US2016329502. Compound VG2 is described in, for example, US20140299192.

[0321] Examples Ex6 to Ex28 also show data for the OLED according to the present invention.

[0322] All materials are applied in a vacuum chamber via thermal vapor deposition. Here, the luminescent layer always consists of at least one matrix material (also the host material) (at least two matrix materials in the sense of this invention) and a luminescent dopant (emitting agent), which is mixed with one or more matrix materials in a specific volume ratio via co-evaporation. The expression E1:IC3:TEG1 (33%:60%:7%) indicates that material E1, as host material 1, exists in the layer at a volume ratio of 33%, compound IC3, as host material 2, exists at a ratio of 60%, and TEG1 exists at a ratio of 7% in a layer with a thickness of 30 nm. Similarly, the electron transport layer can also be composed of a mixture of two materials.

[0323] The OLED was characterized using standard methods. For this purpose, the electroluminescence spectrum and the current / voltage / luminescence density characteristic line (IUL characteristic line) were measured. The EQE and current efficiency SE (in cd / A) were then calculated. SE was calculated from the Lambertian emission characteristics.

[0324] Lifetime LT is defined as the time taken at a constant current density j0 (in mA / cm²). 2 During operation, the luminescence density changes from the initial luminescence density L0 (in cd / m²). 2 (Calculated) decreases to a specific ratio L1 (in cd / m 2 The statement L1 / L0 = 80% in Table 7 indicates that the lifetime indicated in the LT column corresponds to the time (in hours) after the luminous density drops to 80% of its initial value (L0).

[0325] Use of the mixture according to the invention in OLEDs

[0326] The material combination according to the invention can be used in the emissive layer of a phosphorescent green OLED. The combination of compounds E1 to E16 and BC1 to BC17 according to the invention is used as a matrix material in the emissive layer in Examples Ex1 and Ex28, as described in Table 6.

[0327] In a comparison of embodiments of the present invention with corresponding comparative examples (see above), it is clear that embodiments of the present invention exhibit a significant advantage in terms of device lifetime in each case.

[0328] Table 6: Structure of OLED

[0329]

[0330]

[0331]

[0332] Table 7: OLED Data

[0333]

[0334]

[0335] Table 8: Materials Used

[0336]

[0337]

[0338]

[0339]

[0340]

[0341]

[0342]

[0343] Example 2: Synthesis of the host material and its precursors:

[0344] a) 2-Dibenzofuran-1-yl-4,6-diphenyl-1,3,5-triazine

[0345]

[0346] 23 g (110.0 mmol) of dibenzofuran-1-boric acid, 29.5 g (110.0 mmol) of 2-chloro-4,6-diphenyl-1,3,5-triazine, and 21 g (210.0 mmol) of sodium carbonate were suspended in 500 mL of ethylene glycol diamine ether and 500 mL of water. 913 mg (3.0 mmol) of tri-o-tolylphosphine was added to the suspension, followed by 112 mg (0.5 mmol) of palladium(II) acetate, and the reaction mixture was heated under reflux for 16 hours. After cooling, the organic phase was separated, filtered through silica gel, washed three times with 200 mL of water, and then evaporated to dryness. The residue was recrystallized from toluene and dichloromethane / heptane. The yield was 37 g (94 mmol), equivalent to 87% of the theoretical value.

[0347] Similarly, the following compounds can be obtained:

[0348]

[0349]

[0350]

[0351] b) 2-(8-bromodibenzofuran-1-yl)-4,6-diphenyl-1,3,5-triazine

[0352]

[0353] 70 g (190.0 mmol) of 2-dibenzofuran-1-yl-4,6-diphenyl-1,3,5-triazine was suspended in 2000 ml of acetic acid (100%) and 2000 ml of sulfuric acid (95% to 98%). 34 g (190 mmol) of NBS was added in portions to the suspension, and the mixture was stirred in the dark for 2 hours. Water / ice was then added, and the solid was separated and washed with ethanol. The residue was recrystallized from toluene. The yield was 80 g (167 mmol), equivalent to 87% of the theoretical value.

[0354] Similarly, the following compounds were prepared:

[0355]

[0356] In the case of thiophene derivatives, nitrobenzene is used instead of sulfuric acid and elemental bromine is used instead of NBS.

[0357] c) 2,4-Diphenyl-6-[8-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)-dibenzofuran-1-yl]-1,3,5-triazine

[0358]

[0359] 60 g (125 mmol) of 2-(8-bromodibenzofuran-1-yl)-4,6-diphenyl-1,3,5-triazine and 39 g (1051 mmol) of bis(pinacol)diborane (CAS 73183-34-3) were dissolved together in 900 mL of anhydrous DMF in a 500 mL flask under a protective atmosphere and degassed for 30 min. Then, 37 g (376 mmol) of potassium acetate and 1.9 g (8.7 mmol) of palladium acetate were added, and the batch was heated at 80 °C overnight. When the reaction was complete, the mixture was diluted with 300 mL of toluene and extracted with water. The solvent was removed on a rotary evaporator, and the product was recrystallized from heptane. Yield: 61 g (117 mmol), 94% of the theoretical value.

[0360] Similarly, the following compounds were prepared:

[0361]

[0362] d)2-[4-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)dibenzofuran-2-yl]phenyl]-4,6-diphenyl-1,3,5-triazine

[0363]

[0364] 68.7 g (110.0 mmol) of 2,4-diphenyl-6-[8-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)dibenzofuran-1-yl]-1,3,5-triazine, 42 g (110.0 mmol) of 2-(4-bromophenyl)-4,6-diphenyl-1,3,5-triazine, and 21 g (210.0 mmol) of sodium carbonate were suspended in 500 mL of ethylene glycol diamine ether and 500 mL of water. 913 mg (3.0 mmol) of tri-o-tolylphosphine was added to the suspension, followed by 112 mg (0.5 mmol) of palladium(II) acetate, and the reaction mixture was heated under reflux for 16 hours. After cooling, the organic phase was separated, filtered through silica gel, washed three times with 200 mL of water, and then evaporated to dryness. The product was purified by silica gel column chromatography using toluene / CHCl3 (1:1), and finally purified under high vacuum (p = 5 × 10⁻⁶). -7 Sublimed in 1,000 mg / L (99.9% purity). Yield: 64 g (81 mmol), equivalent to 70% of theoretical value.

[0365] The following compounds can be prepared similarly:

[0366]

[0367]

[0368]

Claims

1. An organic electroluminescent device, the organic electroluminescent device comprising an anode, a cathode, and at least one organic layer, the at least one organic layer comprising at least one light-emitting layer, wherein the at least one light-emitting layer comprises at least one compound of formula (1) as host material 1, at least one compound of formula (2a) as host material 2, and at least one phosphorescent material of formula (3). in: Y is selected from O, S, C(phenyl)2 or The * symbol marks the C atom that is bonded to the rest of the formula (1); L is selected from one of the divalent linker groups L-14 to L-23. The linking groups L-14 to L-23 may also be replaced by one or more substituents R; W is either O or S; a is 0 or 1; b is 0 or 1; R is selected from CN each time it appears, either identically or differently, of a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 20 C atoms, of an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, of an aryloxy or heteroaromatic group having 5 to 40 aromatic ring atoms, or of an aralkyl or heteroaromatic group having 5 to 40 aromatic ring atoms; Ar1, in each occurrence, is independently an aryl or heteroaryl group having 5 to 40 aromatic ring atoms, which may be substituted by one or more groups R; K and M, in each case, independently represent an aromatic ring system having 6 to 40 aromatic ring atoms, which is unsubstituted or partially or completely deuterated or monosubstituted by R*. R 0 Each time they appear, they are independent of each other as aromatic ring systems with 6 to 18 C atoms that are either unsubstituted or partially or completely deuterated; R* is dibenzofuranyl or dibenzothiophenylyl; c, d, e, and f are each 0 or 1 independently. When n+m is 3, n is 1 or 2, and m is 2 or 1. X' is N or CR'. R' is H, D, or a branched or straight-chain alkyl group having 1 to 10 carbon atoms, or a partially or fully deuterated branched or straight-chain alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 4 to 7 carbon atoms, said group being partially or fully deuterated, and One of the X's is selected from N and the other X's represent CR'.

2. The organic electroluminescent device according to claim 1, characterized in that... In the main material 1, Y represents O.

3. The organic electroluminescent device according to claim 1, wherein the compound of formula (1) is selected from the following compounds:

4. The organic electroluminescent device according to claim 1, characterized in that... The organic electroluminescent device is an electroluminescent device selected from organic light-emitting transistors (OLET), organic field quenching devices (OFQD), organic light-emitting electrochemical cells (OLEC), organic laser diodes (O-lasers), and organic light-emitting diodes (OLEDs).

5. The organic electroluminescent device according to claim 1, characterized in that... In addition to the light-emitting layer (EML), the organic electroluminescent device also includes a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), an electron injection layer (EIL), and / or a hole blocking layer (HBL).

6. The organic electroluminescent device according to claim 1, wherein the compound of the host material 2 is selected from the following compounds:

7. The organic electroluminescent device according to claim 1, wherein the light emitter of formula (3) is selected from the following compounds:

8. A method for producing a device according to any one of claims 1 to 7, characterized in that... The luminescent layer is applied by vapor deposition or from a solution.

9. The method according to claim 8, characterized in that... The at least one compound of formula (1) and the at least one compound of formula (2a) are deposited from the vapor phase continuously or simultaneously from at least two material sources, optionally together with the at least one phosphorescent emitter, to form the luminescent layer.

10. The method according to claim 8, characterized in that... The at least one compound of formula (1) and the at least one compound of formula (2a) are deposited from the vapor phase as a mixture with the at least one phosphorescent material, either continuously or simultaneously, to form the luminescent layer.

11. The method according to claim 8, characterized in that... The at least one compound of formula (1) and the at least one compound of formula (2a) are applied from the solution together with the at least one phosphorescent material to form the luminescent layer.

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